From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id D994E3858409; Thu, 21 Sep 2023 09:51:16 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D994E3858409
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1695289876;
	bh=+aVDE/VDTKc9TbamU5wnOGPGpf7yuNeu7jxb4Ba60hY=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=dyqJ4q/raKltcPra7v4XcMEtZZEfzsoldGdmI/cUNLk6dC/kyvh6alW8hnG08nRzF
	 f4bUuvvjI6mIV+hY+k5nMgpb44EB0SljCxXphcJFr4gNR3UGzKHO3DPaIaMrXnQBvb
	 ZafHbMvYWV9KNE9TrHGusEzcq+hsNR+DrQz2GEfY=
From: "malat at debian dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/110622] x87: Miscompilation at O2 level (O1 is working)
Date: Thu, 21 Sep 2023 09:51:16 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 13.1.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: malat at debian dot org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-110622-4-KfQVIoG8ke@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-110622-4@http.gcc.gnu.org/bugzilla/>
References: <bug-110622-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D110622

--- Comment #11 from Mathieu Malaterre <malat at debian dot org> ---
Typical setup:

g++ -fno-asynchronous-unwind-tables -fno-exceptions -fno-rtti -DHIDESYMPTOM
-std=3Dc++11 -g -m32 -fexcess-precision=3Dfast -O2 -o works math_test.cc
-Wfatal-errors -Wall -Wextra -Wpedantic -Wconversion -Werror

and:

g++ -fno-asynchronous-unwind-tables -fno-exceptions -fno-rtti -std=3Dc++11 =
-g
-m32 -fexcess-precision=3Dfast -O2 -o fails math_test.cc -Wfatal-errors -Wa=
ll
-Wextra -Wpedantic -Wconversion -Werror

You can observe that the only difference is that I am preventing an elision=
 :

```
% grep -A2 HIDE math_test.cc
#ifdef HIDESYMPTOM
  asm volatile("" : "+r"(y.raw[0]) : : "memory");
#endif
```=